The circulatory system is an organ system that passes nutrients (such as amino acids, electrolytes and lymph), gases, hormones, blood cells, etc. to and from cells in the body to help fight diseases and help stabilize body temperature and pH to maintain homeostasis.

1. Md. Saiful Islam
Dept. of Pharmaceutical Sciences
North South University
Facebook Group: Pharmacy Universe
Youtube Channel: Pharmacy Universe
CARDIOVASCULAR SYSTEM

2. CARDIOVASCULAR SYSTEM
Blood vessels, Anatomy

3. The circulatory system is an organ system
that passes nutrients (such as amino acids,
electrolytes and lymph), gases, hormones,
blood cells, etc. to and from cells in the
body to help fight diseases and help
stabilize body temperature and pH to
maintain homeostasis.
The circulatory system

4. • The cardiovascular system has three
types of blood vessels:
• Arteries (and arterioles) – carry blood
away from the heart
• Capillaries – where nutrient and gas
exchange occur
• Veins (and venules) – carry blood toward
the heart.

6. • Arteries and arterioles take blood
away from the heart.
• The largest artery is the aorta.
• The middle layer of an artery wall
consists of smooth muscle that can
constrict to regulate blood flow and
blood pressure.
• Arterioles can constrict or dilate,
changing blood pressure.

7. • Capillaries have walls only one cell thick to
allow exchange of gases and nutrients with
tissue fluid.
• A collection of capillaries known as
capillary bed. Capillary beds are present in
all regions of the body but not all capillary
beds are open at the same time.
• Contraction of a sphincter muscle closes off
a bed and blood can flow through an
arteriovenous shunt that bypasses the
capillary bed.

9. • Venules drain blood from capillaries,
then join to form veins that take blood
to the heart.
• Veins have much less smooth muscle
and connective tissue than arteries.
• Veins often have valves that prevent
the backward flow of blood when
closed.
The Veins

10. • The heart is a cone-shaped,
muscular organ located between
the lungs behind the sternum.
• A double-layered membrane
called the pericardium surrounds
the heart like a sac.
-The outer layer of the
pericardium (fibrous pericardium)
surrounds the roots of the heart's
major blood vessels and is
attached by ligaments to the
spinal column, diaphragm, and
other parts of the body.
-The inner layer of the pericardium
(Serous pericardium) is attached
to the heart muscle.

11. • The serous pericardium, in turn, is
divided into two layers,
• the parietal pericardium, which is
fused to and inseparable from the
fibrous pericardium, and
• the visceral pericardium, which is
part of the epicardium.
• The pericardial cavity lies
between the visceral
pericardium and the parietal
pericardium. This cavity is filled
with pericardial fluid which
serves as a shock absorber by
reducing friction between the
pericardial membranes and let
the heart moves as it beats.

12. Function of the Pericardium
The pericardium has several functions:
• Keeps the heart contained in the chest cavity.
• Prevents the heart from overexpanding when blood volume
increases.
• Limits heart motion.

13. Three layers of tissue form the heart wall.
The outer layer of the heart wall is the epicardium
/visceral pericardium,
the middle layer is the myocardium, and
the inner layer is the endocardium.
The walls of the heart are largely made from
myocardium, which is a special kind of muscle tissue.
This muscle is so constructed that it is able to perform
the 60 to 70 contractions which the healthy adult
human heart undergoes every minute.
On the inside this muscle is provided with a lining of
flat cells called the endocardium, which is in direct
contact with the blood within the heart.

14. • The heart has four chambers:
two upper, thin-walled atria, and
two lower, thick-walled ventricles.
• The septum is a wall dividing the
right and left sides.
• Atrioventricular valves occur
between the atria and ventricles
– the tricuspid valve on the right
and the bicuspid valve on the
left; both valves are re-enforced
by chordae tendinae attached to
muscular projections within the
ventricles.

15. Coronary Arteries (1-3)
• Because the heart is composed primarily of cardiac
muscle tissue that continuously contracts and relaxes,
it must have a constant supply of oxygen and
nutrients. The coronary arteries are the network of
blood vessels that carry oxygen- and nutrient-rich
blood to the cardiac muscle tissue.
• The blood leaving the left ventricle exits through the
aorta, the body’s main artery. Two coronary arteries
referred to as the "left" and "right" coronary arteries,
emerge from the beginning of the aorta, near the top of
the heart.
• Just like branches on a tree, the coronary arteries
branch into progressively smaller vessels. The larger
vessels travel along the surface of the heart; however,
the smaller branches penetrate the heart muscle.
• The smallest branches, called capillaries, are so
narrow that the red blood cells must travel in single file.
In the capillaries, the red blood cells provide oxygen
and nutrients to the cardiac muscle tissue and bond
with carbon dioxide and other metabolic waste
products, taking them away from the heart for disposal
through the lungs, kidneys and liver.

16. 4. Superior Vena Cava
The superior vena cava is one of the two main
veins bringing de-oxygenated blood from the body
to the heart. Veins from the head and upper body
feed into the superior vena cava, which empties
into the right atrium of the heart
.
5. Inferior Vena Cava
The inferior vena cava is one of the two main veins
bringing de-oxygenated blood from the body to the
heart. Veins from the legs and lower torso feed
into the inferior vena cava, which empties into the
right atrium of the heart.
6. Aorta
The aorta is the largest single blood vessel in the
body. It is approximately the diameter of your
thumb. This vessel carries oxygen-rich blood from
the left ventricle to the various parts of the body.

17. 7. Pulmonary Artery
The pulmonary artery is the vessel
transporting de-oxygenated blood from the
right ventricle to the lungs. A common
misconception is that all arteries carry
oxygen-rich blood. It is more appropriate to
classify arteries as vessels carrying blood
away from the heart.
8. Pulmonary Vein
The pulmonary vein is the vessel transporting
oxygen-rich blood from the lungs to the left
atrium. A common misconception is that all
veins carry de-oxygenated blood. It is more
appropriate to classify veins as vessels
carrying blood to the heart.

18. 9.Right Atrium
The right atrium receives de-oxygenated blood from the body through
the superior vena cava (head and upper body) and inferior vena cava
(legs and lower torso). The sinoatrial node sends an impulse that
causes the cardiac muscle tissue of the atrium to contract in a
coordinated, wave-like manner. The tricuspid valve, which separates
the right atrium from the right ventricle, opens to allow the de-
oxygenated blood collected in the right atrium to flow into the right
ventricle.
10. Right Ventricle
The right ventricle receives de-oxygenated blood as the right atrium
contracts. The pulmonary valve leading into the pulmonary artery is
closed, allowing the ventricle to fill with blood. Once the ventricles are
full, they contract. As the right ventricle contracts, the tricuspid valve
closes and the pulmonary valve opens. The closure of the tricuspid
valve prevents blood from backing into the right atrium and the opening
of the pulmonary valve allows the blood to flow into the pulmonary
artery toward the lungs.
11. Left Atrium
The left atrium receives oxygenated blood from the lungs through the
pulmonary vein. As the contraction triggered by the sinoatrial node
progresses through the atria, the blood passes through the mitral valve
into the left ventricle.
12. Left Ventricle
The left ventricle receives oxygenated blood as the left atrium contracts.
The blood passes through the mitral valve into the left ventricle. The
aortic valve leading into the aorta is closed, allowing the ventricle to fill
with blood. Once the ventricles are full, they contract. As the left
ventricle contracts, the mitral valve closes and the aortic valve opens.
The closure of the mitral valve prevents blood from backing into the left
atrium and the opening of the aortic valve allows the blood to flow into
the aorta and flow throughout the body.

19. 13. Papillary Muscles
The papillary muscles attach to the lower portion of
the interior wall of the ventricles. They connect to the
chordae tendineae, which attach to the tricuspid
valve in the right ventricle and the mitral valve in the
left ventricle. The contraction of the papillary
muscles opens these valves. When the papillary
muscles relax, the valves close.
14. Chordae Tendineae
The chordae tendineae are tendons linking the
papillary muscles to the tricuspid valve in the right
ventricle and the mitral valve in the left ventricle. As
the papillary muscles contract and relax, the chordae
tendineae transmit the resulting increase and
decrease in tension to the respective valves, causing
them to open and close. The chordae tendineae are
string-like in appearance and are sometimes
referred to as "heart strings."

20. 15.Tricuspid Valve/ Right AV valve
The tricuspid valve separates the right atrium from the right
ventricle. It opens to allow the de-oxygenated blood
collected in the right atrium to flow into the right ventricle. It
closes as the right ventricle contracts, preventing blood from
returning to the right atrium; thereby, forcing it to exit
through the pulmonary valve into the pulmonary artery.
16. Mitral Valve/ Left AV Valve
The mitral valve separates the left atrium from the left
ventricle. It opens to allow the oxygenated blood collected in
the left atrium to flow into the left ventricle. It closes as the
left ventricle contracts, preventing blood from returning to
the left atrium; thereby, forcing it to exit through the aortic
valve into the aorta.
Semi lunar valve:
17. Pulmonary Valve
The pulmonary valve separates the right ventricle from the
pulmonary artery. As the ventricles contract, it opens to
allow the de-oxygenated blood collected in the right
ventricle to flow to the lungs. It closes as the ventricles
relax, preventing blood from returning to the heart.
18. Aortic Valve
The aortic valve separates the left ventricle from the aorta.
As the ventricles contract, it opens to allow the oxygenated
blood collected in the left ventricle to flow throughout the
body. It closes as the ventricles relax, preventing blood from
returning to the heart.

21. Pulmonary and Systemic
Circulation
• Systemic Circulation
• Systemic Circulation comprises blood supply to the entire body except the
lungs.
• Heart pumps oxygenated blood to body via arteries
• Returns deoxygenated blood to right heart via veins
• Systemic circulation is a high resistance, high pressure circuit.
• Pulmonary Circulation
• Pulmonary Circulation is circulation to the lungs for removal of carbon
dioxide, other gases, and volatile compounds.
• Heart pumps deoxygenated blood to lungs via pulmonary arteries
• Returns oxygenated blood to left heart via pulmonary veins
• Pulmonary circulation is a low resistance, low pressure circuit

22. Functions of the Heart
• Generating blood pressure
• Routing blood: separates pulmonary and
systemic circulations
• Ensuring one-way blood flow: valves
• Regulating blood supply
– Changes in contraction rate and force match
blood delivery to changing metabolic needs

23. THANK YOU